Screen printing has the characteristics of thick ink layer, rich graphics and graphics, strong stereoscopic effect and wide printing materials. It has gradually increased its application in high-grade tobacco and alcohol and food packaging cartons. The use of UV screen ink to print frosted, refraction, ice, wrinkles and other effects on the cigarette case greatly stimulates the consumer's desire to purchase. However, due to the flat printing speed, the printing speed is low, the ink curing speed is slow, the printing quality is difficult to control, and the printing material is expensive, which cannot meet the needs of the cigarette carton size and mass production. It adopts high-speed rotary screen printing production line, which has fast printing speed, high productivity, stable printing quality and low consumption. It has changed the traditional flat-press screen printing, manual paper feeding and ink supply. It is suitable for high-speed automatic and large-scale mass production. Fold the paper tray.
The web rotary screen printing uses a nickel metal round screen plate, a built-in doctor blade and an automatic ink supply system that transfers the printing ink from the round screen to the surface of the substrate supported by the impression cylinder. The entire printing process is controlled automatically by the computer from paper feeding, ink supply, printing color registration, and UV dry bathing. The circular screen printing plate is made of 100% nickel non-woven fabric material, and the mesh is formed into a hexagonal wire-shaped hole, and the entire mesh surface is even and thin to ensure the stability and precision of the printing. Suitable for large format rotary printing, the maximum speed can reach 125m/min, and the screen can be reused 15 times. Therefore, the web rotary screen printing can meet the requirements of special effects such as printing frosting and ice icing, and can directly print holographic anti-counterfeiting marks, embossing and die-cutting, and realize high-speed automatic printing of paper boxes.
The environmentally friendly UV silk screen imitation metal etching ink is mainly composed of an oligomer (ie, a photocurable resin), a reactive diluent (ie, a photosensitive crosslinking monomer), a photopolymerization initiator, and a filler. Printing on gold and silver cardboard, UV silk screen imitation metal etching ink is quickly cured under ultraviolet light, and the surface of the printed matter has a matte effect.
Under ultraviolet light irradiation, the photopolymerization initiator in the UV ink absorbs photons of a certain wavelength and is excited to an excited state to form a radical or an ion. Then, by the transfer of intermolecular energy, the polymer such as the polymerizable prepolymer and the photosensitive monomer is brought into an excited state to generate a charge transfer complex; the complex is continuously crosslinked and solidified into a film. UV inks are selectively absorbed by photons of ultraviolet light.
The dryness of UV ink is affected by the total energy of the UV light source and the light energy distribution of different wavelengths. Solving the matching of UV ink and UV light source is beneficial to speed up the drying speed of ink, improve labor productivity and energy utilization, and reduce production cost.